British finance minister Rishi Sunak said a U.S. proposal to focus on the world’s 100 biggest and most profitable firms as part of a global tax deal could work but he insisted that big tech firms must pay more tax in countries where they operate.

Sunak told Reuters that the Group of Seven was making “really good progress” on the long-disputed reform before finance ministers from the group of rich economies fly to London for talks on Friday and Saturday.

The meeting will be their first face-to-face encounter since the COVID-19 pandemic struck. It is also the first since Joe Biden replaced Donald Trump as U.S. president, raising hopes for more cooperation between Washington and the rest of the world.

“It’s certainly something we can work with as long as it meets our objectives of getting at the right companies and on the face of it, it can,” Sunak said in an interview, conducted at his office at Number 11 Downing Street, when asked about the U.S. proposal. “We just need to work through the details.”

The plan would simplify the approach to taxing multinational corporations. It would focus on the profits of the 100 biggest companies that have benefitted most from globalisation, chief among them tech giants, which have seen their businesses boom during the pandemic.